For example, methods and arrangements are known from DE-C 39 36 638 wherein, depending upon the on-board voltage, electrical consumers are switched off in groups with a view to the charge balance of the battery. One group is always completely switched off. The arrangement of the groups is static, that is, a specific consumer always belongs to the same group. Furthermore, the reverse case is not covered, namely, that electrical consumers are switched on, for example, because of drive train requirements.
Accordingly, it is necessary to provide a consumer control wherein the switching on and switching off of electrical consumers is coordinated via a higher-ranking consumer management in the context of: a total vehicle control, a vehicle electrical system or an energy management.
A total vehicle control is, for example, described in DE-A 41 11 023 (U.S. Pat. No. 5,351,776), which exhibits a hierarchical command structure for the control tasks. The control structure described there Includes coordination elements which convert a command, which originates from a higher hierarchical level, into commands for elements of a subordinated hierarchical level. The contents of the commands, which are transmitted from above downwardly into the hierarchical structure, define physical quantities which determine the interfaces between the individual hierarchical levels. The described interfaces orientate themselves to the physical conditions of the movement of the motor vehicle and especially of the drive train and of the brakes. A view of a vehicle control which goes beyond the latter while considering the control of the consumers or the energy distribution in the vehicle electrical system is not described.
The principle of a hierarchical base structure of a vehicle total system is known from U.S. Pat. No. 5,991,669. There, a vehicle coordinator is the command giver for the components "drive" (source of mechanical power), "vehicle motion", "chassis and interior space" and "vehicle electrical system" (source of electrical power). The communication between the individual components of this structure takes place only between the higher-ranking component and the components, which are assigned thereto, in the context of fixed pregiven communication relationships. These relationships are the following: the order which is basically given by a component in a higher hierarchical level to a component in a lower hierarchical level and which must be executed by the ordered component; the request which also is given by a component in a lower hierarchical level to a component in a higher hierarchical level and which should be executed by the requested component; and, the inquiry for which an answer is expected from the questioned component to the questioning component. The control of the vehicle takes place in the context of these pregiven communication relationships between the components. For the control of the vehicle, fixed pregiven physical quantities are transmitted which constitute defined interfaces between the individual components. A configuration of the coordinator of the electrical vehicle system or information as to the involvement of the control of electrical consumers is not shown.